1. Field of the Invention
The present invention relates to a solid electrolytic capacitor, and a method of manufacturing the solid electrolytic capacitor.
2. Description of the Related Art
Conventionally, a small solid electrolytic capacitor to be mounted on a surface of a printed circuit board or the like is manufactured by resin-molding a capacitor element including a dielectric layer formed by anodizing valve metal. In response to a demand for an increase in capacitance of a solid electrolytic capacitor, one using niobium oxide serving as a dielectric layer has been attracting attention.
In comparison with tantalum oxide, niobium oxide is susceptible to a heat treatment, and a leakage current tends to increase. For this reason, there are proposed some solid electrolytic capacitors each having a certain element structure (refer to Japanese Patent Publication No. Heisei 11-329902, and Japanese Patent Publication No. 2005-252224). In these solid electrolytic capacitors using niobium oxide, it is made possible to achieve suppression of a leakage current by adding nitrogen or fluorine in a niobium oxide layer.
In the solid electrolytic capacitors including the aforementioned niobium oxide layer, however, there are some cases where a leakage current increases when the produced capacitor element is resin-molded.